api-breakage.yml

name: API Breakage

on:
  pull_request:
    branches: [ "main" ]
    paths-ignore: [ "**.md", "LICENSE" ]
  push:
    branches: [ "main" ]
    paths-ignore: [ "**.md", "LICENSE" ]
  workflow_dispatch:
    inputs:
      baseline:
        description: "Git treeish to compare against (default: latest release tag)"
        required: false
        default: ""

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  api-breakage:
    name: Compare public API with latest release
    runs-on: macos-latest
    steps:
      - uses: actions/checkout@v7
        with:
          fetch-depth: 0
          fetch-tags: true

      - name: Select baseline
        id: baseline
        env:
          REQUESTED: ${{ inputs.baseline }}
        run: |
          if [ -n "$REQUESTED" ]; then
            baseline="$REQUESTED"
          else
            baseline="$(git tag --list --sort=-version:refname | grep -E '^[0-9]+\.[0-9]+\.[0-9]+$' | head -n 1)"
          fi
          if [ -z "$baseline" ]; then
            echo "::error::Could not determine a baseline release tag"
            exit 1
          fi
          echo "Comparing the public API against $baseline"
          echo "baseline=$baseline" >> "$GITHUB_OUTPUT"

      - name: Diagnose API breaking changes
        env:
          BASELINE: ${{ steps.baseline.outputs.baseline }}
        run: |
          set -o pipefail
          status=0
          swift package diagnose-api-breaking-changes "$BASELINE" \
            --products OpenAI \
            --breakage-allowlist-path .github/api-breakage-allowlist.txt \
            2>&1 | tee api-breakage.log || status=$?

          if grep -q "API breakage" api-breakage.log; then
            {
              echo "## 💔 Public API breaks compared with \`$BASELINE\`"
              echo
              echo "Fix each line below, or consciously accept it by adding the exact message on its own line to \`.github/api-breakage-allowlist.txt\` (messages only, no comments) together with a CHANGELOG entry."
              echo
              echo '```'
              grep "API breakage" api-breakage.log
              echo '```'
            } >> "$GITHUB_STEP_SUMMARY"
            echo "::error::Public API breaking changes detected compared with $BASELINE. See the job summary."
            exit 1
          fi

          if [ "$status" -ne 0 ]; then
            echo "::error::swift package diagnose-api-breaking-changes exited with status $status"
            exit "$status"
          fi

          echo "## ✅ No public API breaks compared with \`$BASELINE\`" >> "$GITHUB_STEP_SUMMARY"

      - name: Upload report
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: api-breakage-report
          path: api-breakage.log
          if-no-files-found: ignore